Turns out you can also do decorators in C, this came in handy for something else I had to work on recently. It’s not quite as nice, because functions aren’t first-class, but handy nonetheless.
Here’s what that looks like:
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
|
#include <stdio.h>
typedef int (* const decorableFnType)(int paramOne, int paramTwo);
int functionOne(int paramOne, int paramTwo)
{
printf("functionOne: %d, %dn", paramOne, paramTwo);
return 0;
}
int functionTwo(int paramOne, int paramTwo)
{
printf("functionTwo: %d, %dn", paramOne, paramTwo);
return 0;
}
int functionThree(int paramOne, int paramTwo)
{
printf("functionThree: %d, %dn", paramOne, paramTwo);
return 0;
}
int decorator(int paramOne, int paramTwo, decorableFnType originalFn)
{
printf("decorator precondition!n");
originalFn(paramOne, paramTwo);
return 0;
}
int main(int argc, char **argv)
{
printf("hello, C decorators!n");
functionOne(1, 2);
decorator(1, 2, functionOne);
decorator(1, 2, functionTwo);
decorator(1, 2, functionThree);
return 0;
}
|
The output of which is:
vilimpoc@funky:~$ ./c-decorators
hello, C decorators!
functionOne: 1, 2
decorator precondition!
functionOne: 1, 2
decorator precondition!
functionTwo: 1, 2
decorator precondition!
functionThree: 1, 2
vilimpoc@funky:~$
This might be a bit simplistic, in reality, you’d probably want to decorate a function with a signature like the following, so that you can just change the structure and not bother w/a bajillion function declarations:
|
1 |
typedef int (* const decorableFnType)(SomeStruct * data);
|
Again, not super elegant, but handy.